Vaisala MM70 - Manual (Page 50)

USER'S GUIDE____________________________________________________________________
Calibration and Adjustment of
MMT330 Transmitters
You can check and adjust MMT330 transmitter reading against a
calibrated reference probe of MMP78 or against another reference
condition by using MI70 indicator in communication. Follow the first
4 steps and continue according to the chosen calibration method.
1. Connect the 211339-connection cable between the service port
of the MMT330 transmitter and the bottom connector of the
MI70 indicator. To ensure durable connection, screw the metal
ring (located at the round end of the cable) clockwise until it
tightens up. (Respectively, when disconnecting the cable, first
screw the metal ring counterclockwise until it loosens and then
pull out the plug.)
2. Turn on the indicator.
- In case you use a MMP78 probe as a reference: The reading
of the transmitter is shown on the first or middle row of the
display, depending on the connector port to which the
calibration cable is connected. Value of the port I is shown on
the upper row of the display and the value of the port II on
the lower row of the display. Difference of the readings is
shown on the lowest row.
- In case MI70 is used as an display (without its own probe),
the reading of the MMT330 transmitter is shown on the
display.
3. Remove the MMI330 transmitter unit from the mounting plate
and press the adjustment key once. Adjustment key is located at
the mother board of the transmitter. Now MI70 is starting the
Adjustment mode.
4. Press the OK key to start adjustment.
Field Checking and Adjustment by
Using a Calibrated Reference Probe
When using this adjustment method, start with the steps 1 through 4 in
the section Calibration and Adjustment of MMT330 Transmitters on
page 48. Then proceed as follows:
1. Select a
w
, RH, T or H
2
O (H
2
O can only be checked, not
adjusted). Press the SELECT key.
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